The present invention is directed to coupling devices, and more particularly to a dry disconnect coupling for draining fluid from tanks, containers or the like, and a safety cap therefore.
Various fluid coupling devices have been devised in the art. However, the coupling devices currently in use suffer from a serious disadvantage in that a considerable quantity of fluid is lost during uncoupling of such devices. The use of the conventional fluid coupling devices is especially undesirable in the instances where a particular tank contains fluids which are of a dangerous nature. Another problem associated with these coupling devices is that it is relatively easy to actuate the cooperating coupling member while they are being uncoupled and thereby lose fluid therefrom.
In addition, some of these devices require a number of complicated interlocks and valves to guard against inadvertent or accidental opening and to make certain that the fluid will flow therethrough when the cooperating coupling members are fastened together in fluid flow position. However, such interlocks are expensive to manufacture and require complex assembly and operating procedures. Another problem that has been observed in the use of these fluid coupling devices is that the valves tend to leak due to improper reassembly, and various other parts which are critical for the operation thereof tend to crack and leak due to over-the-road vibrations encountered during transporting of the tanks.
Finally, the conventional coupling devices do not offer adequate protection from an accidental or unexpected fluid spill in the instances where the flow actuating lever or the like may have been left in the flow position and results in the loss of a substantial quantity of fluid when, for example, the safety cap is removed by a user at a different location. The accidental spill is not only an economic loss in terms of the lost fluid, but could also be hazardous to individuals handling the tanks when the fluid is of a dangerous or harmful nature.
An example of a coupler device is disclosed in U.S. Pat. No. 3,473,569.